Circuit board, device mounting structure, device mounting method, and electronic apparatus

ABSTRACT

A circuit board is used in common for the first electronic apparatus as the first configuration and for the second electronic apparatus as the second configuration, and the circuit board includes an area which is used in common for installing the first electronic device in installing the circuit board into the first electronic apparatus, and for installing the second electronic device in installing the circuit board into the second electronic apparatus, wherein the first electronic device is used only for the first electronic apparatus, and the second electronic device is used only for the second electronic apparatus.

This application claims the right of priority under 35 U.S.C. § 119based on Japanese Patent Application No. 2004-145504 filed on May 14,2004, which is hereby incorporated by reference herein in its entiretyas if fully set forth herein.

BACKGROUND OF THE INVENTION

The present invention relates generally to a circuit board, a mountingstructure, a mounting method, and an electronic apparatus, and moreparticularly to a circuit board that is used in common for domestic(i.e., Japanese) market and for overseas market. The present inventionis suitable for a motherboard (main board) that is installed in, forexample, notebook type computers, personal digital assistants (PDA),handy game instruments, handy electronic apparatuses such as driveunits, space saving type electronic apparatuses such as desktopcomputers or word processors of display integrated type or slim type.

The demand for electronic apparatuses such as personal computers is nowgrowing. Particularly, handy data processing apparatuses such asnotebook type personal computers (hereinafter, “note PCs”.) or PDAs areremarkably improving and widespreading, and they are demanded to besmaller and thinner. Furthermore, various functions or apparatuses areinstalled in the handy data processing apparatuses so as to satisfy thedemand for them to have higher performance and more various functions.

However, the demand to be smaller and thinner is basically contrary tothe demand to have higher performance and more various functions. Thedata processing apparatus becomes big in accordance with having morefunctions. Still more, the data processing apparatus (or electronicdevices installed in the data processing apparatus) generally generatesmore heat in accordance with having higher performance or morefunctions. The data processing apparatus will become bigger inaccordance with increasing the functions because it also needs coolingfunction. Therefore, to make the handy data processing apparatus besmall, thin, lightweight, high performance, and various functions, thedecision of installing the higher necessary performances and functionsand not installing the lower necessary performances and functions in thedata processing apparatus is needed.

The necessity of the performances and functions often depends on theconsumer targeted. The consumer targeted can be classified, for example,by consumer's age or market destination (domestic or overseas such as tothe U.S.A. or to Europe). Therefore, the functions to be installed aredifferently selected in accordance with grade or market destination inthe same series of the data processing apparatuses.

In such case for example, a motherboard optimized only for Japanesedomestic market is used for a note PC for Japanese domestic market, anda motherboard optimized only for overseas market is used for a note PCfor overseas market.

However, many kinds of motherboards should be manufactured for oneseries of the data processing apparatus if the exclusive motherboardsare respectively used for every grade or destination. Thus, many kindsof production molds or production lines of the motherboards should beprepared and it results increase of the production cost. Many kinds ofmotherboards confuse the assembling process, and it results decrease ofassembling performance.

BRIEF SUMMARY OF THE INVENTION

Accordingly, it is an exemplary object to provide a novel and usefulcircuit board, a mounting structure, and an electronic apparatus havingthe same. Concretely, it is an exemplary object to provide a circuitboard that can have performances or functions for many grade ordestinations of electronic apparatuses and can be used in common formany grades or destinations, and can decrease the production cost andincrease the assembling performance of the electronic apparatuses.

To achieve above-mentioned objects, a circuit board of one aspectaccording to the present invention is used in common for the firstelectronic apparatus as the first configuration and for the secondelectronic apparatus as the second configuration. The circuit boardincludes an area which is used in common for installing the firstelectronic device in installing the circuit board into the firstelectronic apparatus, and for installing the second electronic device ininstalling the circuit board into the second electronic apparatus,wherein the first electronic device is particularly used for the firstelectronic apparatus, and the second electronic device is particularlyused for the second electronic apparatus.

Here, the electronic apparatus is, for example, a note PC. And a desktoptype personal computer or handy data processing apparatus and the likeis applicable to the electronic apparatus. For example, the firstconfiguration and the second configuration means respectively fordomestic market and for overseas market, or two different grades of theelectronic apparatus. That is, the first electronic apparatus and thesecond electronic apparatus are the same series but differentspecifications (configurations). The first electronic device that isparticularly used for the first electronic apparatus is, for example, afloppy disk drive unit, and the second electronic device that isparticularly used for the second electronic apparatus is, for example,high performance VGA (Video Graphic Array) device which is higherresolution (higher performance) than a standard VGA device. For example,the standard VGA device can display in a resolution of at least 640×480dots, and the high performance VGA device can display in a resolution ofat least 1 280×1024 dots.

As the circuit board can be used in common for domestic market (thefirst configuration) and for overseas market (the second configuration),many kinds of the circuit board do not have to be produced for oneseries of the electronic apparatus (for example, note PC). Therefore, itcan decrease the production cost and increase the assemblingperformance. The floppy disk drive unit (the first electronic device) isinstalled and the high performance VGA device (the second electronicdevice) is not installed in the electronic apparatus for Japanesedomestic market. While, the high performance VGA device is installed andthe floppy disk drive unit is not installed in the electronic apparatusfor overseas market. A specific area is used in common for installingboth devices. In accordance with the destination, the floppy disk driveunit or the high performance VGA device is selectively installed on thespecific area. Therefore, the space in the electronic apparatus will beused more effectively, and the electronic apparatus will become smallerand thinner. The specific area is substantially rectangular shape on thecircuit board and the size of the area is preferably 96 mm×126 mm orlarger. Then, the floppy disk drive unit can be located in the areaeasily, and influence to other devices on the circuit board can beminimized.

The third electronic device may be installed on the circuit board bothin the first configuration and the second configuration, and the secondelectronic device may be used instead of the third electronic devicealternatively. The third electronic device means, for example, thestandard VGA device that is installed in the electronic apparatus forboth domestic market and overseas market. The high performance VGAdevice is used instead of the standard VGA device in the electronicapparatus for overseas market so that it can display with highresolution to satisfy foreign consumer's demand.

The circuit board may be a single board on which a processing circuitthat processes a main control of the first electronic apparatus or thesecond electronic apparatus is installed. The single board may be amotherboard. The processing circuit may be a CPU. If the circuit boardis the motherboard on which the CPU is installed, the space in theelectronic apparatus will be used more effectively and the electronicapparatus will become smaller and thinner.

The first electronic device may include a drive unit for portablestorage media and the second electronic device may include a displaycircuit. For example, the floppy disk drive unit can be used as thedrive unit for portable storage media and the high performance VGAdevice can be used as the display device. In this case, the floppy diskdrive unit or the high performance VGA device can be selectivelyinstalled on the circuit board in accordance with the configuration(destination) of the electronic apparatus. Still, in the specific areaon the circuit board in the electronic apparatus of the secondconfiguration, at least a device to connect an external memory, a deviceto connect a IEEE1394 connector, a device to connect a video connector,a device to connect a USB (Universal Serial Bus) connector, a device forBluetooth, and a connector to connect a cooler to cool the highperformance VGA device may be installed with the high performance VGAdevice. Here, the device to connect the external memory means a driveunit that has a slot to insert the external memory such as SD (SecureDigital) memory, memory stick, and the like. The device to connect theIEEE1394 connector means, for example, a connection port based onIEEE1394 standard, and it can be connected with the digital videocamera, and the like. The device to connect the video connector means,for example, a S-Video connection port, and it can be connected with thevideo unit that has the S-Video connector. The device to connect the USBconnector means USB connection port, and it can be connected withvarious external apparatus that is based on the USB standard. A devicefor Bluetooth means, for example, a wireless communication device totransmit or receive the wireless data that is based on the Bluetoothstandard. These devices are sometimes necessary for the electronicapparatus of the second configuration (for overseas market) and notnecessary for that of the first configuration (for domestic market).Therefore, by arranging these devices in the specific area unitedly,there will be no devices in the specific area on the circuit board inthe electronic apparatus of the first configuration. Thus, the specificarea can be used effectively for other devices or functions.

A cooler to cool the second electronic device may be installed on thecircuit board. The high performance VGA device used as the secondelectronic device generates a lot of heat. However, installing thecooler can minimize a bad influence such as thermal runaway.

The cooler may be installed in the specific area. The first electronicdevice is not installed in the second configuration, and the cooler canbe easily arranged in the specific area. The size, especially thethickness of the electronic apparatus will merely increase.

The cooler may be a heat sink unit that includes a heat receiving platethat receives heat from the second electronic device by contacting thesecond electronic device, a heat conductor that conducts heat from theheat receiving plate to a radiation plate, and a cooling fan that coolsthe radiation plate by blowing. Thus, the cooler can cool the secondelectronic device effectively.

The heat sink unit may have a ventilator that exhausts air from thecooling fan, and the ventilator may be located near a device to connectan external memory that is installed on the circuit board. As the deviceto connect the external memory merely generates heat, the coolingefficiency does not decrease when the ventilator is located near or onthe device. It is not difficult to design the height (i.e., the sizealong the thickness of the electronic apparatus) of the device toconnect the external memory and of the ventilator be small. Therefore,it does not increase the thickness of the electronic apparatus.

An extension connector part may be installed on the circuit board. Here,the extension connector may connect an extension unit that is removabllyattachable to the first electronic apparatus and the second electronicapparatus. As the extension unit or the external apparatus can beattachable to the electronic apparatus via the extension connector part,the expansivity of the electronic apparatus will be improved.

The extension connector part may be installed substantially adjacent toboth the install position of the second electronic device on the circuitboard and the install position of the third electronic device on thecircuit board. The further the extension connector part to connect theextension unit is from the VGA device, the longer the lead cable or thelead pattern between them is, and the bigger the influence of signalnoise is. Therefore, the noise signal will be overlapped on the imagesignal transmitted by the lead cable or the lead pattern, and the VGAdevice cannot put out the performance sufficiently. Thus, the extensionconnector part is preferable to be near the VGA device. By locating theinstall position of the extension connector part substantially adjacentto the install position of the VGA device (the second electronic deviceor the third electronic device), the VGA device will put out itsperformance sufficiently.

The second electronic device may be installed at a position in the areaso that the distance between the extension connector part and the secondelectronic device is substantially the same as the distance between theextension connector part and the third electronic device. By equalizingthe distance from the extension connector part to two VGA devices (thesecond and the third electronic devices), transmission quality of theimage signal will not be different in the first configuration and in thesecond configuration.

The extension connector part may be installed in an overlapped area thatis used both when the circuit board is installed in the electronicapparatus in the first direction and when the circuit board is installedin the electronic apparatus in the second direction.

Here, the first direction is, for example, the width direction of theelectronic apparatus in using state (hereinafter, “width direction”.).The second direction is, for example, the depth direction of theelectronic apparatus in using state (hereinafter, “depth direction”.).On reason for designing, there are two types of the motherboardinstalled in the electronic apparatus. One is a motherboard of widthdirection layout, and the other is that of depth direction layout.While, extension unit is used in common in a lot of electronicapparatuses in spite of the motherboard's layout direction. So, theposition and the shape of the extension connector part are preferablythe same in every kind of the electronic apparatus. By locating theextension connector part in the overlapped area, same extensionconnector part can be used both in the electronic apparatus having themotherboard of width direction layout and in the electronic apparatushaving the motherboard of depth direction layout.

An install position of the extension connector part may be within aspecific distance from a back face of the electronic apparatus when thecircuit board is installed in the electronic apparatus, and within aspecific distance from a centerline of width of the electronicapparatus. For example, the install position of the extension connectorpart may be within 30 mm from the back face of the electronic apparatus,and within 30 mm from the centerline of width of the electronicapparatus when seen from a front face. Thus, the extension unit can beconnected with the electronic apparatus at its back face easily. Thearrangement of the circuit board in the electronic apparatus will becomefree.

The extension unit may be a connection apparatus that has a plurality ofconnectors for peripheral apparatuses. For example, the connectionapparatus may be a port replicator. By connecting the port replicatorwith the electronic apparatus, more external apparatuses can beconnected with the electronic apparatus via the port replicator and theexpansivity of the electronic apparatus improves.

The connection apparatus that has a width substantially the same as thewidth of the electronic apparatus may be removably attachable to theback face of the electronic apparatus. The connection apparatus may havea projection part on which a connector being connectable to theextension connector part is located. As the width of the connectionapparatus is substantially the same as the width of the electronicapparatus, feeling of use and portability of the electronic apparatuswith the connection apparatus attached thereto will be good. Theprojection can make the size or the weight of the connection apparatusbe reduced.

An electronic apparatus of another aspect according to the presentinvention includes the above mentioned circuit board installed therein.Thus, in addition to the above mentioned effects, it can make theelectronic apparatus be small, thin, lightweight, high performance, andvarious functions. If the circuit board is the motherboard, it will notbe necessary to prepare the several different motherboards for everygrade or every destination in one series of the electronic apparatus.Therefore, it can decrease the production cost and increase theassembling performance.

The electronic apparatus may be used in common for the firstconfiguration and for the second configuration, and may have a packagebeing substantially rectangular parallelepiped shape. For example, thesize of the package is 333 mm×285 mm×38 mm or smaller. It can decreasethe production cost and increase the assembling performance because thepackage can be used in common for a plurality of the configurations. Thesize of 333 mm×285 mm×38 mm or smaller can make the notebook typecomputer be small.

The electronic apparatus may be a notebook type computer. Thus, thenotebook type computer will be small, thin, lightweight, highperformance, and various functions. And it can decrease the productioncost and increase the assembling performance of the notebook typecomputer.

A circuit board of still another aspect according to the presentinvention is for an electronic apparatus. The circuit board has aplurality of electronic devices installed on the surface of the circuitboard, and is used in common for at least two configurations. An installposition of at least two electronic devices on the surface of thecircuit board is in a united area. The at least two devices are notinstalled on the surface of the circuit board in the first configurationof the at least two configurations, and are installed on the surface ofthe circuit board in the second configuration of the at least twoconfigurations.

An electronic apparatus of still another aspect according to the presentinvention includes a circuit board that has a plurality of electronicdevices installed on the surface of the circuit board, and is used incommon for at least two configurations. An install position of at leasttwo electronic devices on the surface of the circuit board is in aunited area. The at least two devices are not installed on the surfaceof the circuit board in the first configuration of the at least twoconfigurations, and are installed on the surface of the circuit board inthe second configuration of the at least two configurations. Here, theelectronic apparatus includes at least either the first electronicapparatus or the second electronic apparatus.

As the circuit board is used in common for the domestic market (thefirst configuration) and for the overseas market (the secondconfiguration), it is not necessary to produce many kinds of circuitboards for one series of the electronic apparatus. Therefore, it candecrease the production cost and increase the assembling performance. Ifa function is not installed in the electronic apparatus for domesticmarket and the same function is installed in that for overseas market, aplurality of the electronic devices in relation to the function are notinstalled on the circuit board for domestic market and are installed onthat for overseas market. Arranging these electronic devices in thespecific area unitedly can generate an empty area that has no electronicdevices on the circuit board for domestic market. Thus, it will be easyto install other functions or other units that is necessary for domesticmarket but not necessary for overseas market in the empty area on thecircuit board. Here, the united specific area means, for example, arectangular shape area of a specific extent which has no electronicdevices on the circuit board.

Other objects and further features of the present invention will becomereadily apparent from the following description of the preferredembodiments with reference to accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a notebook type personal computerincluding a motherboard of one embodiment according to the presentinvention.

FIG. 2 is a bottom view of the notebook type personal computer shown inFIG. 1.

FIG. 3 is a whole perspective view of a port replicator used with thenotebook type personal computer shown in FIG. 1.

FIG. 4A is a perspective view seen from front face in the state ofconnecting the port replicator with the notebook type personal computershown in FIG. 1. FIG. 4B is a perspective view seen from back face inthe state of connecting the port replicator with the notebook typepersonal computer shown in FIG. 1.

FIG. 5 is a whole perspective view of the motherboard installed in amain unit of the notebook type personal computer shown in FIG. 1.

FIG. 6A is a perspective view of top face of a heat sink unit to beinstalled in the notebook type personal computer shown in FIG. 1. FIG.6B is a perspective view of bottom face of the heat sink unit to beinstalled in the notebook type personal computer shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[The Explanation of q Notebook Type Personal Computer for OverseasMarket]

Referring now to the accompanied drawings, a description will be nowgiven of a circuit board of one embodiment according to the presentinvention. FIG. 1 is a perspective view of a notebook type personalcomputer 1 (note PC 1) as an electronic apparatus including amotherboard (single board) as one embodiment of a circuit boardaccording to the present invention. The note PC 1 has a display part 2and a main unit 4. The display part 2 is rotatablly connected with themain unit 4 by a hinge, and it can be open and close. This note PC 1 isa computer (the second electronic apparatus) for overseas market (thesecond configuration), and a computer (the first electronic apparatus)for domestic market (the first configuration) in the same series will beexplained later.

The display part 2 is for displaying various information such as movies,pictures, or characters, and uses for example a liquid crystal displayunit (LCD) of 15 inches or 17 inches. The note PC 1 is folded byrotating the display part 2 toward the main unit 4 around the hinge whena user does not use the note PC 1. The display part 2 is opened andraised from the main unit 4 when the user uses the note PC 1.

The main unit 4 has most of basic functions of the note PC 1. Forexample, the main unit 4 includes a keyboard 6, a touch panel 8, and asub display 9 on its surface. The keyboard 6 is an input device by usingthe keys for the user to input information to the note PC 1. The touchpanel is also a kind of input devices, and uses for example anelectrostatic touch sensor. A mouse cursor moves in the display part 2in accordance with the movement of the user's finger on the touch panel8. The sub display 9 indicates a status of the note PC1 such as a poweron/off, a hard disk status, and a battery charge status. For example,the sub display 9 uses LEDs or monochrome LCD.

The main unit 4 further has a power switch (not shown), a PC card driveunit 10, an optical disk drive unit 12 (see also FIG. 4B), SD card driveunit (a device to connect an external memory) 14, a IEEE1394 port 16, aS-Video connection port 18, and a USB port 20 on its side face. The PCcard drive unit 10 is for inserting and connecting the card devices thatis based on the PC card standard and have various functions. The opticaldisk drive unit 12 is for reading the data from CD-ROM. It can havefunctions of reading from or writing to CD-R, CD-RW, DVD-ROM, DVD-R,DVD-RW, or DVD-RAM. The SD card drive unit 14 is for inserting andconnecting the SD card as an external memory. The main unit 4 caninclude a compact flash memory drive unit or memory stick drive unitinstead of the SD card drive unit 14. The IEEE1394 port 16 is forconnecting various apparatuses based on IEEE1394 standard. For example,a digital video camera is connected with the IEEE1394 port 16. TheS-Video connection port 18 is for connecting imaging apparatuses thatoutput S-Video signal. The USB port 20 is for connecting variousapparatuses based on USB standard.

FIG. 2 is a bottom view of the main unit 4 seen from bottom face. Asshown in FIG. 2, the main unit 4 has an extension connector part 22 onits bottom face to connect a port replicator (a connection apparatus) 23as an extension unit (see also FIG. 3). The extension connector part 22is located within 30 mm as a specific distance from a back face 1 a ofthe note PC 1. When seen from a front face 1 b in using state of thenote PC 1, the extension connector part 22 is located within 30 mm as aspecific distance to the left (to the right in FIG. 2) from a centerlineof width of the note PC 1. Thus, shown in FIGS. 4A and 4B, the portreplicator 23 can be attached to or removed from the back face 1 a ofthe note PC 1 easily. As the extension connector part 22 can beinstalled on the motherboard both in the depth direction layout and inthe width direction layout which will be explained later, thearrangement of the motherboard in the main unit 4 becomes free.

FIG. 3 is a whole perspective view of the port replicator 23 as theextension unit. The port replicator 23 includes a connector 23 a to beconnected electrically with the extension connector part 22 on the mainunit 4, a connecting part 23 b to be connected mechanically with theback face 1 a of the main unit 4, and a release button 23 c that is usedto release the port replicator 23 from the main unit 4. The connector 23a is arranged on a projection 23 d partially projected from a main body23 e. The width of the main body 23 e is approximately the same as thewidth of the note PC 1. The port replicator 23 is a connection apparatusthat can connect various apparatuses with the note PC 1 by expanding thefunction of the note PC 1. As shown in FIG. 4B, a lot of ports(connectors for peripheral apparatuses) such as a LAN port 23 j, ananalog RGB output port 23 k, an optical digital output port 23 f, aserial port 23 g, a parallel port 23 h, and a USB port 23 i are locatedon the back face of the port replicator 23. By connecting externalapparatuses with these ports via cables, the note PC 1 can furtherexpand the functions.

The main unit 4 includes a motherboard 24 as a circuit board therein.FIG. 5 is a whole perspective view of the motherboard 24. On the oneside of the motherboard 24, a CPU (a processing circuit) 26, a memory asan information storage device (not shown), a standard VGA device (thethird electronic device, a display circuit) 28, a high performance VGAdevice (the second electronic device, a display circuit) 30, a Bluetoothunit (a device for Bluetooth) 32, and a connector for heat sink unit(connector for cooler) 34 are installed. And the extension connectorpart 22 for the port replicator is installed on the other side of themotherboard 24. A lot of other devices are installed on the motherboard24, and the PC card drive unit 10, a battery 36, and the optical diskdrive unit 12 are also arranged on the motherboard 24.

The motherboard 24 is, for example, a rectangular shape. If themotherboard 24 is arranged with its long side along the width direction(the first direction) of the main unit 4, it is called “width directionlayout”. If the motherboard 24 is arranged with its long side along thedepth direction (the second direction) of the main unit 4, it is called“depth direction layout”. There are width direction layout typemotherboard 24 and depth direction layout type motherboard 24. An areathat is overlapped by width direction layout type motherboard and depthdirection layout type motherboard in the main unit 4 is called anoverlapped area B (the area enclosed by thick line in FIG. 5). Theextension connector part 22 is located in the overlapped area B. Thus,the port replicator 23 can be used in common for the note PC 1 includingthe width direction layout type motherboard and for the note PC 1including the depth direction layout type motherboard because theposition of the extension connector part 22 does not change.

The standard VGA device 28 and the high performance VGA device 30 areboth electronic devices for displaying graphics. They has a function ofprocessing the positions or colors in displaying movies, pictures, orcharacters on the display part 2. The standard VGA device 28 is, forexample, for displaying the movies etc. on the display part 2 with640×480 dots. The high performance VGA device 30 is for example, fordisplaying the movies etc. on the display part 2 with 1280×1024 dots andhas a resolution higher than the standard VGA device does. The Bluetoothunit 32 is a wireless communication device to transmit or receive thewireless data that is based on the Bluetooth standard. The connector 34for heat sink unit is a power supply connector that supplies electricpower to the heat sink unit (the cooler) 38 for the high performance VGAdevice 30, explained later.

On the motherboard 24, the SD card drive unit 10, the IEEE1394 port 16,S-Video connection port 18, the USB port 20, the high performance VGAdevice 30, the Bluetooth unit 32, the connector 34 for heat sink unit aselectronic devices (hereinafter, these seven electronic devices aregenerically called “the electronic devices for overseas only”) areunitedly installed in the specific area A of approximately rectangularshape shown in FIG. 5 as a hatching part. And above the specific area A,the heat sink unit 38 is arranged so as to cover the electronic devicesfor overseas only. FIG. 6A is a perspective view of top face of the heatsink 38 and FIG. 6B is a perspective view of bottom face of the heatsink 38. The heat sink unit 38 includes a heat receiving plate 38 a, aheat pipe (a heat conductor) 38 b, a heat radiation plate (not shown), acooling fan 38 c, and a ventilator 38 d. The heat receiving plate 38 areceives the heat from the high performance VGA device 30 by contactingto the top face of the high performance VGA device 30, the heat isconducted by the heat pipe 38 b to the heat radiation plate located nearthe ventilator 38 d, and the radiation plate is cooled by blowing of thecooling fan 38 c. The blowing air is exhausted to out of the note PC 1through the ventilation 38 d. The ventilation 38 d is provided on a slot38 e for inserting the SD card into the SD card drive unit 14.

This note PC 1 is for overseas market (the second configuration) thatneeds high performance VGA function and Bluetooth function. Therefore,the high performance VGA device 30 and the Bluetooth unit 32 areinstalled on the motherboard 24 in the note PC 1. And more, the heatsink unit for cooling the high performance VGA device 30 is alsoinstalled in the note PC 1. As shown in FIG. 6B, there are not so manydevices near the bottom face of the heat sink unit 38, and the heat sinkunit 38 arranged above the motherboard 24 so as to cover the electronicdevices for overseas only does not interfere to the Bluetooth unit 32 orthe connector 34 for heat sink unit. Therefore, the main unit 4 of thenote PC 1 for overseas market can be thin. The heat sink unit 38 is athin rectangular parallelepiped shape, and the rectangular areaprojected on the motherboard 24 is approximately the same as that of afloppy disk drive unit (a first electronic device, a drive unit forportable storage media) 40 explained later. The projected area is inaccordance with the area of the specific area A. Concretely, theprojected area is not more than the area of the specific area A. Thus,the heat sink unit 38 can be arranged in the range of the specific areaA. The size of the specific area is preferably 96 mm×126 mm or smallerto arrange the heat sink unit 38 or the floppy disk drive unit 40 in therange of the specific area A and to secure the install area for otherdevices on the motherboard 24.

The standard VGA device 28 and the high performance VGA device 30 areinstalled at the position substantially adjacent to the extensionconnector part 22 for the port replicator. These VGA devices can put outtheir performance more sufficiently when they are closer to theextension connector part 22. Two VGA devices 28, 30 are substantiallyadjacent to the extension connector part 22 in the note PC 1, the VGAdevices can put out their performance sufficiently without suffering badinfluence of the noise signal. The distance from the standard VGA device28 to the extension connector part 22 and the distance from the highperformance VGA device 30 to the extension connector part 22 areapproximately the same. Thus, the transmission quality of the imagesignal is approximately the same in the note PC for domestic market andin that for overseas market.

[The explanation of a Notebook type Personal computer for DomesticMarket]

As a note PC 1 for domestic (Japanese) market does not need highperformance VGA function and Bluetooth function, the electronic devicesfor overseas only are not installed on the motherboard 24. The floppydisk drive unit 40 is installed in the main unit 4, because it isdemanded instead of the electronic devices for overseas only. As thehigh performance VGA device 30 is not installed, the heat sink unit 38is not installed either. The floppy disk drive unit 40 is installedabove the specific area A. As the devices for overseas only are notinstalled, the floppy disk drive unit 40 can be arranged right above andvery close to the motherboard 24, the main unit 4 of the note PC 1 fordomestic market can be thin. As the results, the package of the mainunit 4 can be used in common for domestic market and for overseasmarket. The size of the package can be reduced to approximately 333mm×285 mm×38 mm. The area of the specific area A is more than the areaof the floppy disc drive unit 40 projected to the motherboard 24.Therefore, the floppy disk drive unit 40 can be arranged in the range ofthe specific area A.

By arranging the electronic devices for overseas only in the specificarea A unitedly as previously explained, the floppy disk drive unit 40can be arranged in the range of the specific area A with achieving thethin main unit of the note PC 1 for domestic market that does notinclude the electronic devices for overseas only. Therefore, themotherboard 24 can be used in common in the note PC 1 for overseasmarket and for domestic market.

Further, the present invention is not limited to this preferredembodiment, and various variations and modifications may be made withoutdeparting from the scope of the present invention. For example, thepresent invention is not limited to the notebook type personal computer,but can be applied to other various electronic apparatuses such asdifferent types of computers or handy data processing units.

According to the present invention, the circuit board can be used incommon, for example, for a plurality of grades or for domestic marketand for overseas market. It is not necessary to produce many kinds ofthe circuit boards for one series of the electronic apparatus.Therefore, it can decrease the production cost and increase theassembling performance. If a function is not installed in the electronicapparatus for domestic market and the same function is installed in thatfor overseas market, a plurality of the electronic devices in relationto the function are not installed on the circuit board for domesticmarket and are installed on that for overseas market. Arranging theseelectronic devices in the specific area unitedly can generate an emptyarea that has no electronic devices on the circuit board for domesticmarket. Thus, it will be easy to install other functions or other unitsthat is necessary for domestic market but not necessary for overseasmarket in the empty area on the circuit board.

1. A circuit board which is used in common for the first electronicapparatus as the first configuration and for the second electronicapparatus as the second configuration, said circuit board comprising anarea which is used in common for installing the first electronic devicein installing the circuit board into the first electronic apparatus, andfor installing the second electronic device in installing the circuitboard into the second electronic apparatus, wherein the first electronicdevice is particularly used for the first electronic apparatus, and thesecond electronic device is particularly used for the second electronicapparatus.
 2. The circuit board according to claim 1, wherein the thirdelectronic device is installed on the circuit board both in the firstconfiguration and the second configuration, and the second electronicdevice is used instead of the third electronic device alternatively. 3.The circuit board according to claim 1, wherein the circuit board is asingle board on which a processing circuit that processes a main controlof the first electronic apparatus or the second electronic apparatus isinstalled.
 4. The circuit board according to claim 3, wherein the singleboard is a motherboard.
 5. The circuit board according to claim 3,wherein the processing circuit is a CPU.
 6. The circuit board accordingto claim 1, wherein the first electronic device includes a drive unitfor portable storage media and the second electronic device includes adisplay circuit.
 7. The circuit board according to claim 1, wherein acooler to cool the second electronic device is installed on the circuitboard.
 8. The circuit board according to claim 7, wherein the cooler isinstalled in the area.
 9. The circuit board according to claim 7,wherein the cooler is a heat sink unit that comprises: a heat receivingplate that receives heat from the second electronic device by contactingthe second electronic device, a heat conductor that conducts heat fromthe heat receiving plate to a radiation plate; and a cooling fan thatcools the radiation plate by blowing.
 10. The circuit board according toclaim 9, wherein the heat sink unit has a ventilator that exhausts airfrom the cooling fan, and the ventilator is located near a device toconnect an external memory that is installed on the circuit board. 11.The circuit board according to claim 1, wherein an extension connectorpart is installed on the circuit board, said extension connectorconnects an extension unit that is removablly attachable to the firstelectronic apparatus and the second electronic apparatus.
 12. Thecircuit board according to claim 11, wherein the extension connectorpart is installed substantially adjacent to both the install position ofthe second electronic device on the circuit board and the installposition of the third electronic device on the circuit board.
 13. Thecircuit board according to claim 12, wherein the second electronicdevice is installed at a position in the area so that the distancebetween the extension connector part and the second electronic device issubstantially the same as the distance between the extension connectorpart and the third electronic device.
 14. The circuit board according toclaim 11, wherein the extension connector part is installed in anoverlapped area that is used both when the circuit board is installed inthe electronic apparatus in the first direction and when the circuitboard is installed in the electronic apparatus in the second direction.15. The circuit board according to claim 14, wherein an install positionof the extension connector part is within a specific distance from aback face of the electronic apparatus when the circuit board isinstalled in the electronic apparatus, and within a specific distancefrom a centerline of width of the electronic apparatus.
 16. The circuitboard according to claim 11, wherein the extension unit is a connectionapparatus that has a plurality of connectors for peripheral apparatuses.17. The circuit board according to claim 16, wherein the connectionapparatus that has a width substantially the same as the width of theelectronic apparatus is removablly attachable to the back face of theelectronic apparatus, and said connection apparatus has a projectionpart on which a connector being connectable to the extension connectorpart is located.
 18. An electronic apparatus in which a circuit board isinstalled, wherein the circuit board is used in common for the firstelectronic apparatus as the first configuration and for the secondelectronic apparatus as the second configuration, said circuit boardcomprising an area which is used in common for installing the firstelectronic device in installing the circuit board into the firstelectronic apparatus, and for installing the second electronic device ininstalling the circuit board into the second electronic apparatus,wherein the first electronic device is particularly used for the firstelectronic apparatus, and the second electronic device is particularlyused for the second electronic apparatus.
 19. The electronic apparatusaccording to claim 18, wherein the electronic apparatus can be used incommon for the first configuration and for the second configuration, andhas a package being substantially rectangular parallelepiped shape. 20.The electronic apparatus according to claim 18, wherein the electronicapparatus is a notebook type computer.
 21. A circuit board for anelectronic apparatus having a plurality of electronic devices installedon the surface of the circuit board, and used in common for at least twoconfigurations, wherein an install position of at least two electronicdevices on the surface of the circuit board is in a united area, whereinsaid at least two devices are not installed on the surface of thecircuit board in the first configuration of the at least twoconfigurations, and are installed on the surface of the circuit board inthe second configuration of the at least two configurations.
 22. Anelectronic apparatus comprising a circuit board that has a plurality ofelectronic devices installed on the surface of the circuit board, and isused in common for at least two configurations, wherein an installposition of at least two electronic devices on the surface of thecircuit board is in a united area, wherein said at least two devices arenot installed on the surface of the circuit board in the firstconfiguration of the at least two configurations, and are installed onthe surface of the circuit board in the second configuration of the atleast two configurations.